The steady 150 FPS was a pleasant thing to discover during these tests. Even with AI running about. Camera distance was reduced heavily as well as the terrain size. You could technically remove the water, sky and terrain completely and get even better results. I believe you can also divide the textures more, since the camera isn't as close. Performance-wise isometrics preform pretty well in GG.
Somethings I'm going to work on:
Full Room Reveal (rather than just radius of tiles) -
Example
Fog of War -
Example 1,
Example 2
* Activate Enemy Spawns (triggered by opening doors to rooms not yet explored)
* Isometric perspective locking with wall removal -
Example
* Ceiling Ghosting (might require new shader swapping or value changing techniques of future GG versions)
* Pits and Traps
* Multi-Floor (highly complex as it requires creating data for floors, in a modular fashion)
* Rogue-Like (because the structures are entities, it may be possible to have levels build themselves)
Just a few things I'm thinking of poking at while I wait for the next GG version's release.